Pigmented Flashcards
1
Q
CARP pathophysiology
A
- abnormal host reaction to Malasezzia, although only isolated in 50% of cases resulting in abnormal keratinocyte differentiation
- responds to tetracyclines –> ? antibiotic or anti-inflammatory
- Associated with: obesity, insulin resistance, thyroid dysfunction and Cushing disease
2
Q
CARP Histology
A
- Hyperkeratosis and papillomatosis, loss of granular layer
- Increased melanin in the basal cell layer and stratum corneum
3
Q
CARP Clinical
A
1-2 mm hyperkeratotic papules on the turnk that coalesce and form greyish-blue plaques, confluent in centre and reticular on periphery
4
Q
DDx for CARP
A
- AN
- Macular amyloid
- Darier
- Epidermal naevus
- Planar warts
- Pit versicolor
- Seb k
- Retention hyperkeratosis
5
Q
CARP Management
A
- no treatment if no cosmetic bother
- weight reduction/remove offending agent
- First line: minocycline appears to be most beneficial
- Second: topical and systemic antifungals
- Third: low dose isotretinoin
6
Q
Ephiledes epidemiology and pathogenesis
A
- More common in blondes and red heads
- Sun induced melanogenesis and transport of an increased number of fully melanised mealnosomes from melanocytes to keratinocytes
7
Q
Ephelides clinical
A
- Sun exopsed areas
- 1-3 mm in diameter - round, oval or irregular in shape
- Marker of UV induced damage
- High freckle density –> high risk of melanoma
8
Q
Ephelides histo
A
- Keratinocytes have increased melanin content
- Occasionally, melanophages in papillary dermis
9
Q
Ephelides ddx
A
- Simple lentigines
- Solar lentigines
- CALMs
- Junctional naevi
10
Q
Ephelides treatment
A
- Photoprotection
- Lighten: topical retinoids and hydroquinone
- Broadband light therapy
11
Q
CALMS pathogenesis
A
- Increased melanogenesis and increased melanin content in keratinocytes
- Biallelic NF1 inactivation has been identified in melanocytes from CALMs in patients with NF1 and McCune Allbright
12
Q
CALMS clinical
A
- Light brown macule, can be anywhere except mucous membrane
- Usually 2-5 cm
- Dermoscopy: homogenous brown patch, with perifollicular hypopigmentation
- Unilateral
- Associations:
- NF
- McCune Albright
- Triad of macular patches, bony lesions and endo (overactive hormones)
- GNAS gene mutation
13
Q
CALMS histology
A
- Slightly increased melanin content in basilar keratinocytes
- Adnexal epithelium spared of hyperpigmentation
- DOPA stained: density of melanocytes higher in both CALMS and normal adjacent skin
- Melanin macroglobules may be present
14
Q
CALMS ddx
A
- Pigmentary mosaicism - segmental pigmentation disorder, linear naevoid hyperpigmentation
- Early naevus spilus –> before speckles appear
- Becker melanosis
- Mastocytoma
- Mosaic neurofibromatosis
- PIH
- Lentigines, acquired melanocytic naevi
- Flat congential melanocytic naevi
15
Q
CALMS treatment
A
- Never undergoes malignant change
- Laser treatment - need to discuss risks, requires multiple treatments –> 12 CALMS treated with Q switched ruby laser –> 50% developed repigmentation within 6 months
16
Q
Becker melanosis epidemiology
A
- usually acquired
- most often appear second and third decades of life
- M>F
17
Q
Becker melanosis pathogenesis
A
- Organoid hamartoma of ectodermally and mesodermally derived tissues
- Increase in androgen receptors and possibly heightened sensitivity to androgens has been postulated
- For congenital –> ?postzygotic mutations in beta-actin
18
Q
Becker melanosis clinical
A
- second or third decade of life
- sometimes following intense sun exposure
- unilateral, usually upper quadrant of anterior or posterior chest but have been described elsewhere
- ranges from a few centimetres to >15 cm
- Can become slightly thickened with hypertrichosis
- May enlarge for a year or 2, then stabilise
- No malignancy change ever been reported
- Associated hypoplastic changes: hypoplasia of the breast, areola, nipple, arm, scoliosus, etc
- More likely to have associated changes in females
19
Q
Becker melanosis histo
A
- Acanthosis, hyperkeratotisis +/- mild papillomatosis
- Regular elongation of the rete ridges and hyperplasia of the pilosebaceous unit
- Melanin content in keratinocytes increased
20
Q
Becker melanosis ddx
A
CALM, congenital melanocytic naevus, plexiform neurofibroma, congenital smooth muscle hamartoma
21
Q
Becker melanosis Rx
A
- Electrolysis, waxing, camouflage makeup
- Laser treatments - Q switched ruby and NdYAD –> recurrence rates are high
